title: A Model-Independent Approach to Dark Energy Cosmologies: Current and Future Constraints
creator: Guarnizo Trilleras, Alejandro
subject: ddc-530
subject: 530 Physics
description: The effective anisotropic stress eta = − Phi/Psi	 is a key variable in the characterisation of the physical  origin of the dark energy. It is however important to use a fully model-independent approach when  measuring eta to avoid introducing a theoretical bias into the results. We forecast the precision  with which future large surveys can determine eta in a way that only relies on directly observable  quantities, using the joint combination of Galaxy Clustering, Weak Lensing and Supernovae probes.  Among the results, we find that a future large scale survey can constrain eta to within 10% if k-independent,  and to within 60% if it is restricted to follow the Horndeski model. In order to  find current constraints on eta data for the growth rate f sigma_8 coming from Redshift Space Distortion  measurements, observations of the Hubble expansion H(z), and a constraint for the quantity  P2 defined as the expectation value of the ratio between galaxy-galaxy and galaxy-velocity cross  correlations, have been used. We find a value at z = 0.32 of eta = 0.646 +/- 0.678, in agreement with  the predicted value for the LCDM model. Finally, we produce a cosmological exclusion plot for  modified gravity in analogy with the exclusion plots produced in laboratory experiments.
date: 2016
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/20369/1/PhD_Thesis_Alejandro_Guarnizo.pdf
identifier: DOI:10.11588/heidok.00020369
identifier: urn:nbn:de:bsz:16-heidok-203698
identifier:   Guarnizo Trilleras, Alejandro  (2016) A Model-Independent Approach to Dark Energy Cosmologies: Current and Future Constraints.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/20369/
rights: info:eu-repo/semantics/openAccess
rights: Please see front page of the work (Sorry, Dublin Core plugin does not recognise license id)
language: eng